I'm definitely not confusing it with seventh heaven. . .I don't know how they do it in NY, but down here cloud nine is just being really happy. I would never use cloud nine in the way poli used it. These are a couple songs with the expression 'cloud nine' in the chorus. The first seems to be closer to my definition, and the second closer to yours.
http://www.youtube.com/watch?v=DW7oa...eature=related
http://www.youtube.com/watch?v=MBxFTzxc0Bo